SUMMARYThis study concludes that one of the connotations of Hebrew tiro(w)s was "psychoactive drug/opium; juice; sauce", which clears up an anomalous line in Tosefta Nedarim 4 (quoted in M. Jastrow's Hebrew dictionary). The reason for this "hidden" meaning is due to the fact of its probably belonging to the spoken or slang (colloquial) language of the times. A parallel to this is the case of the English "weed" or "sauce". Jastrow's failing to see this meaning lies in a deliberate secrecy in the ancient world surrounding drug use. A good parallel is offered concerning Arabic and Persian ti/aryag "theriaca, wine, opium". Also, the literature on tiro (w) s is extensively reviewed.